^No tear down plans, though some still have to be refurbished before being rented out. No new housing, other than places that are being refurbished and aren't open yet.
Anyone can rent, the military has no involvement with the Presidio any longer. There are some preferences and low income housing set-asides for employees of the various employers in the Presidio (non-profits, Lucas Arts). The rental prices are
absurd - it's baffling to me that they're able to charge the prices that they're getting, but vacancy is essentially zero (the only folks that I've met who have rented there have been on corporate relocation and/or share a place with 10 roommates -
$3700 for 1350 sq ft in a crappy 60's building, many of the older houses are $8-10,000+ a month). You can rent similarly-sized places in nearby (very, very nice) neighborhoods for less. I used to live very near the Presidio and loved it, but I wouldn't want to live in it - too disconnected from retail/restaurant areas.
It's a national park, so the only restrictions would be those put in place by the park service. I think there are technically "closed" times in the middle of the night like Golden Gate Park has, but I've walked through at all times and you can certainly drive through at any time. The only "restricted" areas are places like the golf courses and the two freeways with fencing around, but the rest is criss-crossed with trails that anyone can use. (And again, no military restrictions of any kind, as the military has no involvement with it any longer).